8 Replies Latest reply: Aug 4, 2012 11:09 AM by Shootist007
Kirk Carver Level 1 (5 points)

I have a MacBook Pro (15-inch Mid 2009), Mac OS X (10.6.8) whose battery has begun to drain relatively quickly.  I get 2 hours out of it if I'm lucky, simply browsing or looking at email.  I need some assistance determining if I need to try to buy a new battery or if something else is causing an issue.  Here is some of the data on my machine:


MacBook Pro (15-inch Mid 2009), Mac OS X (10.6.8)


Model Name:          MacBook Pro

  Processor Name:          Intel Core 2 Duo

  Processor Speed:          3.06 GHz

  Number Of Processors:          1

  Total Number Of Cores:          2

  L2 Cache:          6 MB

  Memory:          4 GB

  Bus Speed:          1.07 GHz

  SMC Version (system):          1.48f2



Battery Information:

Manufacturer:          SMP

  Device name:          bq20z451

  Pack Lot Code:          0000

  PCB Lot Code:          0000

  Firmware Version:          0003

  Hardware Revision:          0003

  Cell Revision:          0100

  Charge Information:

  Charge remaining (mAh):          1973

  Fully charged:          No

  Charging:          No

  Full charge capacity (mAh):          5673

  Health Information:

  Cycle count:          122

  Condition:          Normal

  Battery Installed:          Yes

  Amperage (mA):          -1447

  Voltage (mV):          11064


System Power Settings:


  AC Power:

  System Sleep Timer (Minutes):          0

  Disk Sleep Timer (Minutes):          10

  Display Sleep Timer (Minutes):          10

  Wake On AC Change:          No

  Wake On Clamshell Open:          Yes

  Wake On LAN:          Yes

  Display Sleep Uses Dim:          Yes

  GPUSwitch:          2

  Battery Power:

  System Sleep Timer (Minutes):          10

  Disk Sleep Timer (Minutes):          10

  Display Sleep Timer (Minutes):          2

  Wake On AC Change:          No

  Wake On Clamshell Open:          Yes

  Current Power Source:          Yes

  Display Sleep Uses Dim:          Yes

  GPUSwitch:          2

  Reduce Brightness:          Yes



Thanks for any help or direction in this matter.



MacBook Pro (15-inch Mid 2009), Mac OS X (10.6.8)
  • maxruddock123 Level 1 (5 points)

    Hi Kirk,


    Have you tried calibrating your battery recently? If not, the instructions to do so are here: http://support.apple.com/kb/HT1490At - Doing this allows for OSX to give a much more accurate battery time, and also allows for the full remaining capacity of the battery to be registered.


    Your stats show 122 counts, I would expect a lot longer battery life. Can you tell me if the stats you've posted where from a fully charged state?


    Post back the stats after you've calibrated, and hopefully that will have sorted the problem.

  • Kirk Carver Level 1 (5 points)


    Thank you for posting.  I tried to access the link you provided, but the URL returned nothing.  Might you have typed the incorrect path?



  • Kirk Carver Level 1 (5 points)


    If you meant this article:


    I have a 2009 Macbook Pro.  According to the article, my battery does not need to be calibrated.



  • clintonfrombirmingham Level 7 (30,000 points)

    You're correct - you battery does not need to be calibrated and trying to do so would do more harm than good.


    Your battery stats look good - very few cycles for a 2009 machine, battery health is "Normal," etc.  While a battery replacement may help with gaining some battery life, everything that you post indicates that your battery is in good shape.


    How many hours have you been able to run on battery in the past?



  • Kirk Carver Level 1 (5 points)



    Thanks for the reply.


    In the past, it seems I would be able to run 4-5 hours before the battery started getting low enough that I'd need to grab a charger.  Nothing scientific, just memory.


    Lately, it seems the fan will run, the machine will get hot, and the battery appears to only last a 2 hours before it drops to the same "need to get the charger" level.


    I probably need to track this with some hard data, noting what the processing load is during use.  Any suggestions other than noting start time, reading the % guage, then noting stop time and %?



  • clintonfrombirmingham Level 7 (30,000 points)

    Go to the App Store and search for an download the free app called "Battery Health"... you can run it while under battery power and it allows you to just keep an eye on your battery's health without going to System Report.


    What's unusual is that you're battery is reporting normal while your getting low life. It's difficult to say if a ne battery would help matters.


    Use Battery Health to keep an eye on your % and times and also run Activity Monitor, in your Utilities folder, to make sure that you don't have any runaway processes while you're under battery power.


    Good luck,



  • Kirk Carver Level 1 (5 points)


    Thank you.  I downloaded that application and will monitor things over the next few days.


    I also performed something called an SMC Reset since my fan had been running quite a bit. The procedure is detailed here:




  • Shootist007 Level 6 (16,660 points)

    Fans running more then you remember can be caused by dust build up in and around them. This will make the system hotter then if there was no dust. Try blowing the system out with some Low Pressure air, Max 40PSI.


    If you like you can take the bottom off and do a good cleaning of the whole fan, heat sink & heat dissipation fin area. This will also make the battery last longer as the fans won't run as much trying to cool the system down.


    But in the end it may be getting close to the time you will need a new battery. The battery will only last so long before it starts to fail and your system is 3+/- years old. This will happen whether you use it all the time or leave it connected to the AC all the time or switch AC and battery power on a regular basis. From your cycle count you don't use it on battery much which in the long run can have the same effect as using the battery all the time.